[unreadable] This proposal is to develop new Doppler ultrasound technology for automatic diagnostic mapping of blood flow in the basal arteries of the brain. These vessels include the middle cerebral artery, the anterior cerebral artery, and the posterior communicating artery. This technology will enable transcranial Doppler diagnostic workup of the acute stroke patient for the rank-and-file emergency department physician, something not currently possible because of the expertise required to utilize transcranial Doppler in any setting. The Phase I SBIR work, from which this proposal moves forward, successfully demonstrated feasibility of the technology with particularly important demonstration of the fast signal processing algorithms for rapid location of flow signals in the angular territory viewable by the ultrasound beam. This technology is needed to quickly and simply provide diagnosis of pathological blood flow conditions that indicate acute stroke in progress, or the risk of stroke, as well as to selectively apply ultrasound to basal arteries of the brain during thrombolytic therapy for stroke. This technology also presents the potential for dramatically increasing the application to a much wider range of health professionals to obtain important diagnostic information with high sensitivity and specificity, and without the utilization frustrations experienced by current users both in locating and maintaining blood flow signals. The emergency department, the operating room, and the vascular laboratory all represent awaiting markets. Phase II targets significant enhancements to the technology demonstrated in Phase I, including increased angular viewing capability for mapping flow in multiple cerebral vessels. The work proposed will result in a prototype platform to explore a new ultrasound modality from which decisions can be made regarding production prototyping for each of the markets noted above. A device for automatic location of and fast mapping, tracking, and monitoring of blood flow in the basal arteries of the brain represents a major commercial market potential. [unreadable] [unreadable]